This invention pertains to applicators for herbicides to be used in killing weeds in row crops and more particularly to a wick-type applicator in which the wick is localized and the application of herbicide to the wicks is selective both in time and location.
Weed control in row crops has always been a problem. Weeds use up both soil nutrients and moisture which could better be used by the planted crop. Therefore, control of weeds has been an unending problem.
Early farmers and gardeners usually used physical methods of removing weeds. Hand pulling or hoeing of weeds are the gardeners methods. Cultivators--in reality, powered hoes--were the early farming methods. The cultivator did two things. It disturbed the earth between the rows, thereby uprooting plants in that area; and it moved dirt from between the rows to within the row to cover plants lower than the crop within the row. Moving the earth and cutting into it require considerable power, however, and are not in the least selective so that frequently a lot of power was expended needlessly.
Recently, chemical means of weed control have become more common. Herbicide chemicals adapted to kill selected types of plants have been developed and are widely used. Some kinds of these chemicals may be injected into the soil at planting time or later and are effective in keeping weeds down. Other kinds of weed sprays may be applied after planting.
Various applicators are used for the kind of chemicals which kill the weed because of contact between the chemical and the plants. Aerial spraying is sometimes used, but is often avoided because of the drifting of the material into neighboring fields which may be planted to crops which might be damaged by the herbicide used. Spraying by use of a sprayer mounted on a farm tractor or pulled by one is also used.
A more recent development is the use of a wick-type applicator in which a wick in the form of a cable stretched along a bar is pulled through a field. The wick is saturated with a liquid herbicide of the desired type which may be specific as to the types of plants to be destroyed. As the wick is then pulled through the field, any plant brushed by the wick will be subject to the action of the herbicide. This method works well, particularly in fields where the weeds to be destroyed are taller than the crop to be preserved so that the wick will brush against the taller weeds.
There are some drawbacks to the wick device, however. The principal drawback is economic. The current wick-type applicators require the whole wick to be saturated all the time. Since herbicides are relatively expensive, this results in excessive cost when there are commonly only certain individual plants or small areas of plants to be sprayed.
That drawback is emphasized by the recent development of the "bean-buggy" type of device in which individuals ride on a tractor-carried or tractor-pulled device. Each individual carries a small sprayer or a nozzle from a larger sprayer with which he or she can apply the spray directly to the weeds in the row or adjacent rows over which the operator is being carried. This system too, becomes expensive if the individual operators are paid wages.
Another advantage of my device resides in the fact of a reduced use of herbicides. By using wicks and herbicide to control only weeds within the plant rows and using physical uprooting of weeds between the rows, I provide complete control of the weeds using a minimum amount of herbicide. Thus, contamination of the soil by the heribicide is kept to an absolute minimum while getting full control of the weeds.
By my invention, I provide a wick-type applicator for a herbicide in which the tractor operator can selectively apply herbicide to individual wicks over the crop rows and the herbicide is used only when weeds are present. This system substantially reduces the amount of herbicide used and therefore the cost to the farmer.